Topper vs no-topper

on average is the aerodynamics of a truck topper going to outweigh the wheight of the topper efficiancy wise?

Where I'm from we call them canopy or shell, but in my opinion the wind restance is by far worse on milage than a shell would be, many in my area drop or completely remove the tailgate, and/or install those rope tailgates.

"Where I'm from we call them canopy or shell," Or a truck cap. Or he could be talking about a tonneau cover.

k lets go with shell as the official terminology, and I am NOT refering to a tonneau cover.

Well OK dude...don't get your underwear in a knot!!!

....many in my area drop or completely remove the tailgate, and/or install those rope tailgates.

Which actually decreases gas mileage!! Mythbusters did an episode and investigated that.

the weight of a canopy will have no noticable affect on your gas mileage

tailgate down and tonneau covers gives the worst gas mileage

while driving an air bubble gets formed in the bed of the truck so the air passes over it with ease, similar to how it does over a canopy and just like it does on the suburban. Its the same principals.

With a canopy the only noticable times for lower gas mileage would be when you have the bed loaded down with a substantial amount of weight or if your pulling a trailer. Which would be the same as not having a canopy at all.

I've got an aluminum topper/canopy/shell. And I "tested" this theory out for myself by driving it with it on for a tank of gas, and then without for a tank of gas. The problem with my "test" is the difference in city/hwy driving. It wasn't exactly the same with both experiments, but I was pleasantly surprised when I found there wasn't any noticable difference in mileage. Now as far as a fiberglass topper/canopy/shell-I couldn't tell you, except they are heavy! I can and have removed my topper/canopy/shell by myself. But my dad has to have help with his fiberglass topper/canopy/shell because of its weight.

I would say whether you get a topper or not depends on what you use your truck for. If you do a lot of hauling they are a pain in the backside to get off the truck. As for mileage you wont notice a difference for or against. It just really depends on what you want to do with your truck.